Question

1. Pore numbers of soil mass can:

Choose one option:

A) Be zero

B) Never get higher than 1.0

C) Take any value

D) Only have a value between zero and 1.0

2. Shear strength of soils:
Choose one option:

A) Decreases with reduction in normal voltage

B) Is inversely proportional to the friction angle of the earth

C) Decreases with increase in normal voltage

D) Is directly proportional to the friction angle of the earth

Increased effective voltage in the earth causes:
Choose one option:

A) Increase in pore count and decrease in permeability

B) Increase in both pore number and permeability

C) Reduction of both pore number and permeability

D) Reduction of pore numbers and increase of permeability

Geotechnical Parameters for long-term, drained effective voltage analyzes:
Choose one option:

A) attraction, a, pore pressure parameters, D and friction angle, φ

B) Attraction, a and friction angle, φ

C) Pore pressure, U

D) Attraction, a

E) Friction Angle, φ

F) Undrained shear strength su (cu)

Geotechnical Parameters for short-term, undrained analyzes:
Choose one option:

A) Friction angle, ϕ

B) Attraction, a and friction angle, ϕ

C) Pore pressure, U

D) Undrained shear strength su (cu)

E) Attraction, a, pore pressure parameters, D and friction angle, ϕ

F) Attraction, a

Answer 1

1. Pore numbers of soil mass can:

Option d)Only have a value between zero and 1.0

Reason : Because Porosity of sandy soil 0.43 and 0.36 and that of clay porosity is between 0.58 and 0.51.

2. Shear strength of soils

Reason: "Shear strength of soil material decreases with decrease of cohesive strength while normal stress and angle of internal friction remain same" (Chaulya, 1993). This decrease in shear strength reduces stability of dump. Shear strength of spoil material also decreases as the angle of internal friction decreases, which in turn reduces stability of the dump.

option d) Hence shear strength of soil is directly proportional to the friction angle of the earth.

3. Increased effective voltage in the earth causes:

option b) Increase in both pore number and permeability since effective voltage is directly proportional to them.

4. Geotechnical Parameters for long-term, drained effective voltage analyzes:

Long-term analysis is carried out in terms of effective stresses, using drained shear strength parameters c' and phi'.

hence option E) Friction Angle, φ

5. Geotechnical Parameters for short-term, undrained analyzes:

Short-term analysis is carried out in terms of total stresses, using undrained shear strength parameters cu and phi = 0.

Hence option D) Undrained shear strength su (cu)